There was no significant difference in fertilization rates between ICSI and conventional IVF (relative risk [RR] 0.99, 95% confidence interval [CI] 0.93-1.06; P = .8). Heterogeneity was observed between studies (I2 = 58.2; P less then .05). Heterogeneity was significant (I2 = 57.1; P less then .05) when cycles with prior fertilization failure were excluded; however, when analysis was restricted to poor responders (RR 1.01, 95% CI 0.97-1.05; P = .6), heterogeneity was no longer significant (I2 = 0.0; P = .5). CONCLUSIONS No difference was found in fertilization rates between conventional IVF and ICSI. Further studies are needed to assess the impact of ICSI in this population, controlling for other indications such as preimplantation genetic testing. Published by Elsevier Inc.OBJECTIVE To study the association between prepregnancy subnormal body weight and obstetrical outcomes after autologous in&nbsp;vitro fertilization (IVF) cycles. DESIGN Systematic review and meta-analysis. SETTING Not applicable. PATIENT(S) Women with prepregnancy subnormal body weight (body mass index less then 18.5 kg/m2) and normal body weight (body mass index 18.5-25 kg/m2) after assisted reproductive treatment. INTERVENTIONS(S) None. MAIN OUTCOME MEASURE(S) Clinical pregnancy rate (CPR), live birth rate (LBR), and miscarriage rate. CPR and LBR were calculated at per-woman and per-cycle levels. RESULT(S) A total of 38 cohort studies with low risk of bias were included. Meta-analyses showed that, compared with normal-weight women, those underweight before pregnancy had a lower CPR at per-woman and per-cycle levels. Compared with normal weight, underweight before pregnancy had little impact on LBR at both per-woman and per-cycle levels, nor on miscarriage rate. CONCLUSION(S) Compared with women of normal weight, women who were underweight before pregnancy had modest association with a lower CPR, but underweight did not seem to affect LBR or miscarriage after IVF. "Once a new technology rolls over you, if you're not part of the steamroller, you're part of the road." -Stewart Brand. OBJECTIVE To provide evidence-based recommendations to practicing physicians and others regarding the effectiveness and safety of therapies for unexplained infertility. METHODS ASRM conducted a literature search, which included systematic reviews, meta-analyses, randomized controlled trials, and prospective and retrospective comparative observational studies published from 1968 through 2019. The ASRM Practice Committee and a task force of experts used available evidence and informal consensus to develop evidence-based guideline recommendations. MAIN OUTCOME MEASURE(S) Outcomes of interest included live-birth rate, clinical pregnancy rate, implantation rate, fertilization rate, multiple pregnancy rate, dose of treatment, rate of ovarian hyperstimulation, abortion rate, and ectopic pregnancy rate. RESULT(S) The literature search identified 88 relevant studies to inform the evidence base for this guideline. RECOMMENDATION(S) Evidence-based recommendations were developed for the following treatments for couples with unexplained infertility natural cycle with intrauterine insemination (IUI); clomiphene citrate with intercourse; aromatase inhibitors with intercourse; gonadotropins with intercourse; clomiphene citrate with IUI; aromatase inhibitors with IUI; combination of clomiphene citrate or letrozole and gonadotropins (low dose and conventional dose) with IUI; low-dose gonadotropins with IUI; conventional-dose gonadotropins with IUI; timing of IUI; and in&nbsp;vitro fertilization and treatment paradigms. CONCLUSION(S) The treatment of unexplained infertility is by necessity empiric. For https://www.selleckchem.com/products/ars-853.html , the best initial therapy is a course (typically 3 or 4 cycles) of ovarian stimulation with oral medications and intrauterine insemination (OS-IUI) followed by in&nbsp;vitro fertilization for those unsuccessful with OS-IUI treatments. This document provides guidance, background, and tips on how to recognize quality trials and focuses on evaluating the validity, importance, and relevance of clinical trial results. This document replaces the document of the same name, last published in 2008 (Fertil Steril® 2008;90S114-20). Scientific research using human embryos advances human health and offspring well-being and provides vital insights into the mechanisms for reproduction and disease. #link# Research involving human embryos is ethically acceptable if it is likely to provide significant new knowledge that may benefit human health, well-being of the offspring, or reproduction. The use of frozen-thawed embryo transfer (FET) has increased over the past decade with improvements in technology and increasing live birth rates. FET facilitates elective single-embryo transfer, reduces ovarian hyperstimulation syndrome, optimizes endometrial receptivity, allows time for preimplantation genetics testing, and facilitates fertility preservation. FET cycles have been associated, however, with an increased risk of hypertensive disorders of pregnancy for reasons that are not clear. Recent evidence suggests that absence of the corpus luteum (CL) could be at least partly responsible for this increased risk. In a recent prospective cohort study, programmed FET cycles (no CL) were associated with higher rates of preeclampsia and preeclampsia with severe features compared with modified natural FET cycles. FET cycles are commonly performed in the context of a programmed cycle in which the endometrium is prepared with the use of exogenous E2 and P. In these cycles, ovulation is suppressed and therefore the CL is absent. The CL produces not only E2 and P, but also vasoactive products, such as relaxin and vascular endothelial growth factor, which are not replaced in a programmed FET cycle and which are hypothesized to be important for initial placentation. Emerging evidence has also revealed other adverse obstetrical and perinatal outcomes, including postpartum hemorrhage, macrosomia, and post-term birth specifically in programmed FET cycles compared with natural FET cycles. Despite the widespread use of FET, the optimal protocol with respect to live birth rate, maternal health, and perinatal outcomes has yet to be determined. Future practice regarding FET should be based on high-quality evidence, including rigorous controlled trials.